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            <h2 class="title" style="clear: both"><a id="reptransport"></a>DbEnv::rep_set_transport()</h2>
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      <pre class="programlisting">#include &lt;db_cxx.h&gt;
 
int
DbEnv::rep_set_transport(int envid,
    int (*send)(DB_ENV *dbenv,
    const Dbt *control, const Dbt *rec, const DbLsn *lsnp,
    int envid, u_int32_t flags));</pre>
      <p>
         The <code class="methodname">DbEnv::rep_set_transport()</code> method initializes the communication
         infrastructure for a database environment participating in a replicated application.
    </p>
      <p>
         The <code class="methodname">DbEnv::rep_set_transport()</code> method is not called by most
         replication applications.  It should only be called by Base API applications
         implementing their own network transport layer, explicitly holding
         replication group elections and handling replication messages outside
         of the Replication Manager framework.
    </p>
      <p>
         The <code class="methodname">DbEnv::rep_set_transport()</code> method configures operations
         performed using the specified <a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>  handle, 
         not all operations performed on the underlying database environment.
    </p>
      <p>
         The <code class="methodname">DbEnv::rep_set_transport()</code> method may be called at any time
         during the life of the application.
    </p>
      <p>
         The <code class="methodname">DbEnv::rep_set_transport()</code> <span>
            
            <span>
                method either returns a non-zero error value or throws an
                exception that encapsulates a non-zero error value on
                failure, and returns 0 on success.
            </span>
        </span>
    </p>
      <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
        <h3 class="title">Note</h3>
        <p>
                    Berkeley DB is not re-entrant. The callback function
for this method should not attempt to make
                    library calls (for example, to release locks or close open handles). Re-entering
                    Berkeley DB is not guaranteed to work correctly, and the results are undefined.
            </p>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp9677216"></a>Parameters</h3>
            </div>
          </div>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp9665376"></a>envid</h4>
              </div>
            </div>
          </div>
          <p>
                          The <span class="bold"><strong>envid</strong></span> parameter is the local
                          environment's ID.  It must be a non-negative integer and uniquely identify
                          this Berkeley DB database environment (see 
                          <a href="../../programmer_reference/rep_id.html" class="olink">Replication environment IDs</a> 
                          for more information).
                     </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp9674096"></a>send</h4>
              </div>
            </div>
          </div>
          <p>
                          The <span class="bold"><strong>send</strong></span> callback function is used to
                          transmit data using the replication application's communication
                          infrastructure.  The parameters to <span class="bold"><strong>send</strong></span> are as follows:
                     </p>
          <div class="itemizedlist">
            <ul type="disc">
              <li>
                <p>
                <code class="literal">dbenv</code>
            </p>
                <p>
                 The <span class="bold"><strong>dbenv</strong></span> parameter is the enclosing
                 database environment handle.
            </p>
              </li>
              <li>
                <p>
                <code class="literal">control</code>
            </p>
                <p>
                 The <span class="bold"><strong>control</strong></span> parameter is the first of
                 the two data elements to be transmitted by the <span class="bold"><strong>send</strong></span> function.
            </p>
              </li>
              <li>
                <p>
                <code class="literal">rec</code>
            </p>
                <p>
                 The <span class="bold"><strong>rec</strong></span> parameter is the second of
                 the two data elements to be transmitted by the <span class="bold"><strong>send</strong></span> function.
            </p>
              </li>
              <li>
                <p>
                <code class="literal">lsnp</code>
            </p>
                <p>
                 If the type of message to be sent has an LSN associated with it, then
                 the <span class="bold"><strong>lsnp</strong></span> parameter contains the LSN
                 of the record being sent. This LSN can be used to determine that
                 certain records have been processed successfully by clients.
            </p>
              </li>
              <li>
                <p>
                <code class="literal">envid</code>
            </p>
                <p>
                 The <span class="bold"><strong>envid</strong></span> parameter is a positive
                 integer identifier that specifies the replication environment to which
                 the message should be sent (see <a href="../../programmer_reference/rep_id.html" class="olink">Replication environment IDs</a> for more
                 information).
            </p>
                <p><a id="transport_DB_EID_BROADCAST"></a>
                The special identifier <code class="literal">DB_EID_BROADCAST</code> indicates that a message
                should be broadcast to every environment in the replication group.  The application
                may use a true broadcast protocol or may send the message in sequence to each
                machine with which it is in communication.  In both cases, the sending site should
                not be asked to process the message.
            </p>
                <p>
                The special identifier 
                <a href="../../programmer_reference/rep_id.html#rep_id.DB_EID_INVALID" class="olink">DB_EID_INVALID</a>
                indicates an invalid environment ID.  This may be used to initialize
                values that are subsequently checked for validity.
            </p>
              </li>
              <li>
                <p>
                <code class="literal">flags</code>
            </p>
                <p>
                 The <span class="bold"><strong>flags</strong></span> parameter must be set to 0
                 or by bitwise inclusively <span class="bold"><strong>OR</strong></span>'ing
                 together one or more of the following values:
            </p>
                <div class="itemizedlist">
                  <ul type="circle">
                    <li>
                      <p><a id="transport_DB_REP_ANYWHERE"></a>
                     <code class="literal">DB_REP_ANYWHERE</code>
            </p>
                      <p>
                 The message is a client request that can be satisfied by another
                 client as well as by the master.
            </p>
                    </li>
                    <li>
                      <p><a id="transport_DB_REP_NOBUFFER"></a>
                  <code class="literal">DB_REP_NOBUFFER</code>
            </p>
                      <p>
                 The record being sent should be transmitted immediately and not
                 buffered or delayed.
            </p>
                    </li>
                    <li>
                      <p><a id="transport_DB_REP_PERMANENT"></a>
                  <code class="literal">DB_REP_PERMANENT</code>
            </p>
                      <p>
                 The record being sent is critical for maintaining database integrity
                 (for example, the message includes a transaction commit).  The
                 application should take appropriate action to enforce the reliability
                 guarantees it has chosen, such as waiting for acknowledgement from one
                 or more clients.
            </p>
                    </li>
                    <li>
                      <p><a id="transport_DB_REP_REREQUEST"></a>
                  <code class="literal">DB_REP_REREQUEST</code>
            </p>
                      <p>
                 The message is a client request that has already been made and to
                 which no response was received.
            </p>
                    </li>
                  </ul>
                </div>
              </li>
            </ul>
          </div>
          <p>

                    It may sometimes be useful to pass application-specific data to the send
                    function; see <a href="../../programmer_reference/env_faq.html" class="olink">Environment FAQ</a>
                    for a discussion on how to do this.

            </p>
          <p>
                    The <span class="bold"><strong>send</strong></span> function must return 0 on success and non-zero on failure.
                    If the send function fails, the message being sent is necessary to maintain database integrity, and
                    the local log is not configured for synchronous flushing, the local log will be flushed; otherwise,
                    any error from the <span class="bold"><strong>send</strong></span> function will be ignored.
            </p>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp9712080"></a>Errors</h3>
            </div>
          </div>
        </div>
        <p>
                         The <code class="methodname">DbEnv::rep_set_transport()</code> <span>
            
            <span>
                method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 
                exception, encapsulating one of the following non-zero errors, or return one
                of the following non-zero errors:
            </span>
        </span>
                    </p>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp9732112"></a>EINVAL</h4>
              </div>
            </div>
          </div>
          <p>
                The method is called from a Replication Manager application; or an invalid flag value or 
                parameter was specified.
            </p>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp9731032"></a>Class</h3>
            </div>
          </div>
        </div>
        <p>
                <a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>  
            </p>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp9732368"></a>See Also</h3>
            </div>
          </div>
        </div>
        <p>
                     <a class="xref" href="rep.html#replist" title="Replication and Related Methods">Replication and Related Methods</a> 
                </p>
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